Constructing a novel synergistic flame retardant by hybridization of zeolitic imidazolate framework‐67 and graphene oxide for thermoplastic polyurethane
Qinyong Liu, Huawei Wang, Hefu Li, Jun Sun, Xiaoyu Gu, Sheng Zhang
Abstract
Abstract To enhance the flame retardancy and smoke suppression of thermoplastic polyurethane (TPU), a novel flame retardant ZIF‐67@GO was fabricated by hybridization of zeolitic imidazolate framework‐67 (ZIF‐67) and graphene oxide (GO). The flame retardancy of TPU sample was significantly enhanced by the presence of 6.5 wt% ammonium polyphosphate (APP) and 0.5 wt% ZIF‐67@GO: the limit oxygen index (LOI) reached 27.4% and UL‐94 grade passed V‐0, the peak heat release rate (pHRR) and peak smoke production rate (pSPR) values was dropped by 81.2% and 48.7%, respectively, comparing with that of the control sample. The burning time of the flame‐retardant TPU sample was prolonged to more than 600 s from 200 s of the control TPU sample during the cone test. Additionally, the tensile strength and elongation ratio of the flame‐retardant TPU reached 18.3 MPa and 1026.3%, respectively, which meet the requirement in most industrial applications. This work provides useful information to produce flame retardant synergists for polymeric composites.